Bob_cassette_rewinder

Original Article ↗ Hacker News Discussion ↗

Cassette system, DRM, and hacking

  • Many compare Bob’s detergent cassettes to inkjet cartridges: proprietary, track usage via EEPROM, and potentially firmware‑updatable to block hacks.
  • The rewinder project is praised as a clever, well-documented hack that completely bypasses or resets this tracking at a fraction of cassette cost.
  • Debate over whether Bob “has DRM”:
    • One side: any mechanism you must bypass or trick to avoid ongoing purchases is DRM.
    • Other side: because the machine works with an empty cassette and manual detergent, it’s not true lock‑in, just an optional system.

Use of non‑cassette detergent

  • Multiple owners confirm Bob runs fine with standard powder or tablets; cassette can be left empty to satisfy the presence check.
  • Some note the cassette allows precise multi‑stage dosing (pre‑wash, main wash, rinse aid), but suggest refillable tanks would be a better design.

Cost and value of cassettes

  • The quoted price (~£43 for 90 washes) is seen by some as extremely high; others note this is comparable to premium full‑size dishwasher tablets when adjusting for added rinse aid and cleaners.
  • Critics argue the cassette addresses no real user problem (“who needs help measuring detergent?”) and mainly exists to create a recurring revenue stream.

Environmental and sustainability debate

  • Strong criticism of calling the product “eco” while using proprietary plastic cartridges.
  • Supporters point out cassettes are officially returnable and reusable, and the dishwasher itself can be more space‑ and water‑efficient for small apartments.
  • Skeptics question:
    • How many cassettes are actually returned and reused.
    • The environmental impact of shipping empties back and forth.
    • The lack of user incentive (no significant discount for returns).
  • Some see this as “greenwashing” and analogous to “SaaS for hardware” with dark patterns around ongoing refills.

Rinse aids and detergent chemistry

  • Side discussion about rinse aid toxicity:
    • One commenter warns about surfactants potentially damaging gut lining at very low concentrations.
    • Others note the cited study was on commercial rinse aids and tissue models; typical household concentrations appear far lower but still “possibly concerning.”
  • Several users report no noticeable benefit from rinse aid, especially with soft water, and some use only salt. DIY rinse‑aid recipes with citric acid and mild surfactants are mentioned.

Dishwasher convenience vs necessity

  • A few argue small loads could easily be hand‑washed in minutes, calling dishwashers “convenience addiction.”
  • Others counter that most people waste more water and heat when hand‑washing, and that compact machines like Bob serve an important niche in tiny kitchens.

Electronics and DIY aspects

  • The cassette rewinder PCB is described as simple; newcomers are advised to:
    • Start with Arduino tutorials, then design in KiCad.
    • Source parts via major distributors or cheaper alternatives.
    • Not avoid SMD components; modern small SMD is seen as manageable and often easier to work with than through‑hole.